Circuit breaker



Sept. 26, 1933. J. SLEPIAN 7,

CIRCUIT BREAKER Filed Jan. 26, 1951 5 Sheets-Sheet l W/T/VE55E'5. INVENTOR a /o5 eph S/ep/an.

ATTORN EY J. SLEPIAN 1,927,904

CIRCUIT BREAKER Filed Jan. 26, 1931 3 Sheets-Sheet 3 Sept. 26, 1933.

F/lg 4 IFIII 0 .0 7 J I 0 w H s M INVENTOR Joseph 5/ep/em ATTORN WITNESSES:

Patented Sept. 26, 1933 CIRCUIT fiREAKER Joseph Slcpian, Wilkinsburg,' t a, assignor to Westinghouse Electric & Manufacturing Company, a corporation of Pennsylvania Application January 26, 1931. Serial No. 511,184

1% Claims.

My invention relates to circuit breakers and more particularly to arc-extinguishing devices capable of opening high-voltage, large-current arcs in air.

Such circuit breakers have been constructed in which the arcs are drawn and moved into deionizing structures comprising pluralities of closely spaced plates between which the arcs are split into pluralities of short arcs which are retated by radial magnetic fields until the zero points on the alternating-current waves are reached, when the arcs are extinguished.

My invention relates to a further development of circuit breakers of the type disclosed in the copending application of F. B. Johnson, Serial No. 510,981 filed January 24, 1931, assigned to the assignee of this application.

An object of my invention is to provide a circuit breaker having a plurality of deionizing plates, each of which is surrounded by a magnetic plate and which has a conducting loop extending around the iron plates to set cup magnetic lines of force therein to provide a field for moving the are into the deionizing-plate spaces. This construction provides a strong entering field and eliminates the use of multi-turn blow-in center of the annular path about which the arc is rotated. Connections are so made to the conducting loop that the current flow in the member through the center of the radial field is in the same direction as the current flow in the arc.

This causes the arc to be attracted to the inside of its annular path and prevents it from being blown from between the deionizing plates by the fibw of gases between them.

These and other objects and advantages of my invention will be more apparent from the following description of the specific embodiment of my invention shown in the accompanying drawings, in which Figure 1 is a diagrammatic view, partially in section, through a circuit breaker embodying my invention, and

Fig. 2 is a sectional view through the circuit breaker of Fig. 1 on the line-II-II.

Fig. 3 is a sectional view through the are extinguisher taken on the line III-III of Fig. 2.

Figs. 4, 5, 6 and '7 are elevational views show- 'ing thedetails of elements used in the are extinguisher.

My invention comprises a circuit breaker 11 having a pair of main contacts 13 and 15 which are connected to the lines 17 and 19 of the circuit to be opened. A pair of arcing contacts 21 and 23 are connected in parallel with the main contacts 13 and 15. The main and arcing contacts are so actuated by any suitable operating mechanism that the main contacts 13 and 15 are opened first, with no appreciable arc, and the circuit is then opened by the arcing contacts 21 and 23.

The movable contact 23 is provided with a movable arc horn 25 which transfers the arc to a pair of stationary arc horns 2'7 and 29 on which the arc is moved into the deionizing structure comprising groups 31 of main deionizing plates and coil sections 33 placed between such groups.

As shown in Figs. 1 and 3, the groups of deionizing plates 31 comprise a plurality of con-' ducting plates 35 which may be of copper, and a plurality of magnetic plates 3'7, which may be of iron. The copper plate 35 is so placed within an opening in the iron plate 37 that the plates are disposed in the same plane in edge-to-edge relation.

The composite plates formed by the iron plates 37 and the copper plates 35 are spaced apartby insulating members 39, 41, 43 and 45 of fish paper. Each of the plates 35 has a converging slot 4'7 therein in a narrow extension 49 at the lower end 35 an annular path 53 around which the arc is rotated by a radial magnetic field. The tip 55 of the slots 4'7 is curved so as to be substantially tangent to the annular path 53.

Each of the radial field-coil sections 33 comprises a radial coil 5'7 which is electrically connected to a pair of coil-end plates 59 on each side thereof. A coil-end transfer plate 61 extends below, and in the same plane with, each of the coilend plates 59.

A plurality of transfer plates 63 are placed betweenthe coil-end plates and spaced apart by insulating sheets 65 of fish paper. Each of the coil-end transfer plates 61 and the transfer plates 63 is provided with a slot 67 which is of less length and greater taper than the slots 4'7 in the main deionizing plates 35. A ventilating opening 69 extends from one side of the annular arc path 53 to the top of the stack so that each short are is individually vented.

The magnetic circuit formed by the iron plates 3'7 is extended to a point beside the separable contacts and are horns by a plurality of iron laminations '71. The laminations '71 are spaced apart by sheets of fish paper '73. a

As shown in Fig. 1, the laminated members '71 are of different lengths. The group of laminations '75 adjacent to each of the stationary arc horns are made of such a length as to extend beside the arc horns. The section of laminations '77 extends to a point beyond the arcing contacts 21 and 23 adjacent to the main contacts 13 and 15 to act on any are which may be drawn therebetween. The intermediate section of laminations.

'79 is of such length as to extend to a point beside the moving arc horn 25.

It is thus seen that the iron laminations '71 constitute a continuation of the iron yokes 3'7 around the copper plates to provide a magnetic field for moving the arc from the arcing contacts into the deionizing structure. Fibre plates 81 protect the edges of the iron laminations '71 from the arc and have inserts 83 of arc-resisting material, such as asbestos. The laminations '71 are secured in place by being clamped between wood blocks 85, and are insulated from the deionizing plates by sheets 86 of fish paper.

A magnetizing winding 87 is provided/for energizing the magnetic circuit formed by iron plates 3'7 and '71. The winding 8'7 comprises a conducting bar 89 extending through'aligned holes in all of the plates and is enclosed in an insulating tube 91 of a fibrous material impregnated with a condensation resin. The return. path comprises a similar conductor 93 in an insulating tube 95.

Each of the insulating tubes 91 and 93 has a plurality of layers of tin foil 92 and 94 imbedded therein for the purpose of equalizing the dielectric stresses on the insulation.

The conducting bars 89 and 93 are connected, at one end, by a conductor 97. The other end of bar 89 is connected to the line 1'7 by a conductor 99, while the end of conducting bar 93 is connected, by a conductor 101, to the upper end oi arc horn 27 which is provided with a currentcarrying portion 103 insulated from the arcterminal portion 105 except at its inner end.

The opposite arc horn 29 is similarly provided with an-arc-terminal portion 107 and a currentconducting portion 109, which is electrically connected, by a conductor 111, to the opposite side of the line 19.

After the arc is drawn between the contacts 21 and 23, it is immediately attracted to the iron are horn 2'7, due to the local fields 'set up in the iron. This causes a short are between the stationary contact 21 and the arc horn'2'7 which is in shunt with the magnetizing loop 8'7. Since the voltage drop through the winding 87 :is less than that required to maintain the arc, the short arcis extinguished, and the conducting loop is inserted in series with the arc. As the arc is continued to be drawn,-the end of the are drawn by movable contact 23 is transferred, by the ion moving arc horn 25, to the stationary arc horn 29 which is also made of iron.

It is thus seen that the first section of the arc which is drawn-acts to insert the magnetizing I winding in the circuit so that a magnetic field is provided immediately for moving the arc on'the arc horns. This prevents any serious burning of the contactsor arc horns. The movement of the arc upwardly on the arc horns is further aided by the magnetic reaction between the current flowing in the arc-terminal portions 105 and 107 bar 89 so attract each other that the arc is held of the arc horns and the current flowing in the arc stream.

From the arrows on the drawings, which show the direction of current flow through the circuit breaker, it is seen that the direction of current flow in the conducting bar 89 is in the same direction as the current in the arc stream. This means that, as the arc is rotated around the annular path 53, the currents in the arc and in the near the inner side of the annular path. This is very desirable since it prevents any possibility of the are being blown out of the vent 69 by the fiowof gases.

Since it is desirable to keep the annular arc path 53 as small as possible, the conducting bar 89 is made of only sufiloient size to carry line current without undue heating, while the conducting bar 93 is made larger in order'that it may be utilized' as a structure member for securing the top portion of the stack of plates and coils together. The lower portions of the stack members are secured together by a pair of rods 115 of a material such as wood impregnated with a condensation resin which support the lower edges of the plates, and have metal end caps 113.

A static shield is provided in the form of a pair of plates 117 of insulating material, such as fibre impregnated with a condensation resin, one of which is placed on each side of the stack of plates. A conducting sheet 119, of tin foil is imbedded in each of the plates 117 so that the condenser action between the metal sheet 119 and the deionizing plates will equalize the potential between the deionizing plates.

While a specific embodiment of the invention has been described, it should be understood that various modifications may be made and that the different features may be used in difierent combinations. My invention should, therefore, not be limited to the specific structure shown, except as defined by the following claims.

I claim as my invention:

1. In an arc-extinguishing structure, a plurality of plates of non-magnetic conducting material, a plurality of plates of magnetic material positioned in planes parallel to said plates of nonmagnetic conducting material, and an electrical conductor extending .through said non-magnetic conducting plates for setting up lines of flux in said magnetic plates.

2. In an arc-extinguishing structure, means of conducting material having ventilating passages therebetween, a plurality of members of magnetic material having ventilating passages therebetween continuous with said ventilating passages between said means of conducting material, said members of magnetic material surrounding said means ,of conducting material, and a conductin loop extending around said members of magnetic 5 material for setting up lines of flux therein for moving they are into said means of conductin material.

3. In an arc-extinguishing structure, a plurality of non-magnetic conducting plates, means for moving the are between said non-magnetic conducting plates comprising a plurality of magnetic plates each of which is disposed with edge portions engaging one of said non-magnetic conducting plates, and a conducting member connected in an electrical circuit extending through said magnetic plates.

4. In an arc-extinguishing structure, a plurality of conducting plates having converging slots therein, a plurality of magnetic plates each'of which has edge portions engaging one of said conducting plates, said magnetic plates having portions extending beside said slots, and a magnetizing coil around said magnetic plates for causing a lateral magnetic field across said slots.

5. In an arc-extinguishing structure, means of conducting material for aiding extinction of the arc, a plurality of members of magnetic material having open spaces therebetween and having wide portions surrounding said means of conducting material and narrow portions adjacent to the entrance to said means of conducting material, and a current conductor extending through said magnetic members for causing a field to move said are into said means of conducting material.

6. In an arc-extinguishing structure, means of conducting material for aiding extinction of the are, a plurality of members of magnetic material having open spaces therebetween surrounding said means of conducting material, and a con-,

ducting member extending through all of said magnetic members and connected in an electrical circuit so that the direction of current flow in said conducting member shall be in the same direction as the, flow of current in said arc.

'7. In an arc-extinguishing structure, a plurality of conducting plates, means for moving the are between said conducting plates comprising a plurality of magnetic plates each of which is disposed with an edge portion engaging one of said conducting plates, and a conducting member connected in an electrical circuit extending through holes in said conducting plates.

8. In an arc-extinguishing structure, means for drawing the arc, a plurality of composite plates having central portions of non-magnetic material and edge portions of magnetic material having an air gap thereacross adjacent said means for drawing the arc, a current conductor extending through said central portions, and means for rotating the are on said central portions about said current conductor.

9. In an arc-extinguishing structure, means for drawing the arc, a plurality of composite plates having central portions of non-magnetic material and edge portions of magnetic material having an air gap thereacross adjacent said means for drawing the arc, a current conductor extending through said central portions, and means for rotating the are on said central portions about said current conductor, said current conductor being so connected that the direction of current flow in both said conductor and said are is the same.

10. In an arc-extinguishing structure, a plurality of plates of conducting material, and a plurality of plates of magnetic material positioned in planes parallel to and having edge portions in engagement with said plates of conducting material, and an electrical circuit for setting up lines of flux in said magnetic plates for moving the are into said conducting plates, and means for rotating said are between said conducting plates and around one side of said electrical circuit.

11. In an arc-extinguishing structure, a plurality of conducting plates and a plurality of magnetic plates having spaces therebetween, means defining an annular path for the are between said conducting plates, a ventilating passage leading from said annular path to between said magnetic plates, means for rotating the are about said annular path, and means forexerting a force on-said arc to oppose movement thereof out of said ventilating passage comprising a conductor extending through the centerof said annular path and carrying current in the same direction as said are.

12. In a circuit interrupter, a pair ofseparable contacts for drawing an are which when extinguished finally interrupts the circuit, a plurality of non-magnetic plates, a plurality of magnetic plates positioned in planes parallel to said nonmagnetic plates, a conducting loop extending around said magnetic plates, said conducting loop being unenergized when the circuit interrupter is closed, and means for utilizing the first section of said are which is drawn to insert said conducting loop in circuit with the arc.

13. In a circuit interrupter, a pair of separable contacts for drawing an are, an arc horn adjacent to said contacts, a plurality of non-magnetic plates, a plurality of magnetic plates positioned in planes parallel to said non-magnetic plates, and a conducting loop extending around said magnetic plates and electrically connected between one of said contacts and said are horn and said conducting loop forming the only electrical connection between said contact and said. are

horn.

14. In an arc extinguishing structure, a plurality of non-magnetic conducting plates, means for moving the are into said non-magnetic conducting plates including a plurality of magnetic plates each of which is disposed with an edge portion engaging one of said non-magnetic conducting plates and insulated from the other of said non-magnetic conducting plates and the other of said magnetic plates, through ventilating passages extending from between said nonmagnetic conducting plates to between said magnetic plates and to the outside of said structure, and a conducting member connected in an electrical circuit extending through holes in said nonmagnetic conducting plates to energize said magnetic plates to move the arc.

JOSEPH SLEPIAN. 

